David Hamilton Koch is an American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 businessman, philanthropist, political activist, and chemical engineer. He is a co-owner (with older brother Charles

Charles G. Koch

Charles de Ganahl Koch is co-owner, chairman of the board and chief executive officer of Koch Industries Inc., the second-largest privately held company by revenue in the United States according to a 2010 Forbes survey...

) and an executive vice president of Koch Industries

Koch Industries

Koch Industries, Inc. , is an American private energy conglomerate based in Wichita, Kansas, with subsidiaries involved in manufacturing, trading and investments. Koch also owns Invista, Georgia-Pacific, Flint Hills Resources, Koch Pipeline, Koch Fertilizer, Koch Minerals and Matador Cattle Company...

, a conglomerate that is the second-largest privately held company in the U.S. Koch is the second-richest resident of New York City

New York City

New York is the most populous city in the United States and the center of the New York Metropolitan Area, one of the most populous metropolitan areas in the world. New York exerts a significant impact upon global commerce, finance, media, art, fashion, research, technology, education, and...

 as of 2010.

He is a major patron of the arts and a funder of conservative and libertarian

Libertarianism

Libertarianism, in the strictest sense, is the political philosophy that holds individual liberty as the basic moral principle of society. In the broadest sense, it is any political philosophy which approximates this view...

 political causes, including some organizations that fund some organizations within the American Tea Party movement

Tea Party movement

The Tea Party movement is an American populist political movement that is generally recognized as conservative and libertarian, and has sponsored protests and supported political candidates since 2009...

.